Commit Graph

361 Commits

Author SHA1 Message Date
Chuck Lever fc788f64f1 nfsd: Limit end of page list when decoding NFSv4 WRITE
When processing an NFSv4 WRITE operation, argp->end should never
point past the end of the data in the final page of the page list.
Otherwise, nfsd4_decode_compound can walk into uninitialized memory.

More critical, nfsd4_decode_write is failing to increment argp->pagelen
when it increments argp->pagelist.  This can cause later xdr decoders
to assume more data is available than really is, which can cause server
crashes on malformed requests.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-08-24 18:05:30 -04:00
J. Bruce Fields 630458e730 nfsd4: factor ctime into change attribute
Factoring ctime into the nfsv4 change attribute gives us better
properties than just i_version alone.

Eventually we'll likely also expose this (as opposed to raw i_version)
to userspace, at which point we'll want to move it to a common helper,
called from either userspace or individual filesystems.  For now, nfsd
is the only user.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-07-12 15:55:00 -04:00
Christoph Hellwig 63f8de3795 sunrpc: properly type pc_encode callbacks
Drop the resp argument as it can trivially be derived from the rqstp
argument.  With that all functions now have the same prototype, and we
can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-05-15 17:42:25 +02:00
Christoph Hellwig 026fec7e7c sunrpc: properly type pc_decode callbacks
Drop the argp argument as it can trivially be derived from the rqstp
argument.  With that all functions now have the same prototype, and we
can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15 17:42:24 +02:00
Christoph Hellwig 8537488b5a sunrpc: properly type pc_release callbacks
Drop the p and resp arguments as they are always NULL or can trivially
be derived from the rqstp argument.  With that all functions now have the
same prototype, and we can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15 17:42:23 +02:00
Trond Myklebust b26b78cb72 nfsd: Fix up the "supattr_exclcreat" attributes
If an NFSv4 client asks us for the supattr_exclcreat, then we must
not return attributes that are unsupported by this minor version.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Fixes: 75976de655 ("NFSD: Return word2 bitmask if setting security..,")
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-05-10 14:30:10 -04:00
J. Bruce Fields f961e3f2ac nfsd: encoders mustn't use unitialized values in error cases
In error cases, lgp->lg_layout_type may be out of bounds; so we
shouldn't be using it until after the check of nfserr.

This was seen to crash nfsd threads when the server receives a LAYOUTGET
request with a large layout type.

GETDEVICEINFO has the same problem.

Reported-by: Ari Kauppi <Ari.Kauppi@synopsys.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-05-10 14:25:19 -04:00
David Howells a528d35e8b statx: Add a system call to make enhanced file info available
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.

The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode.  This change is propagated to the vfs_getattr*()
function.

Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.

========
OVERVIEW
========

The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.

A number of requests were gathered for features to be included.  The
following have been included:

 (1) Make the fields a consistent size on all arches and make them large.

 (2) Spare space, request flags and information flags are provided for
     future expansion.

 (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
     __s64).

 (4) Creation time: The SMB protocol carries the creation time, which could
     be exported by Samba, which will in turn help CIFS make use of
     FS-Cache as that can be used for coherency data (stx_btime).

     This is also specified in NFSv4 as a recommended attribute and could
     be exported by NFSD [Steve French].

 (5) Lightweight stat: Ask for just those details of interest, and allow a
     netfs (such as NFS) to approximate anything not of interest, possibly
     without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
     Dilger] (AT_STATX_DONT_SYNC).

 (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
     its cached attributes are up to date [Trond Myklebust]
     (AT_STATX_FORCE_SYNC).

And the following have been left out for future extension:

 (7) Data version number: Could be used by userspace NFS servers [Aneesh
     Kumar].

     Can also be used to modify fill_post_wcc() in NFSD which retrieves
     i_version directly, but has just called vfs_getattr().  It could get
     it from the kstat struct if it used vfs_xgetattr() instead.

     (There's disagreement on the exact semantics of a single field, since
     not all filesystems do this the same way).

 (8) BSD stat compatibility: Including more fields from the BSD stat such
     as creation time (st_btime) and inode generation number (st_gen)
     [Jeremy Allison, Bernd Schubert].

 (9) Inode generation number: Useful for FUSE and userspace NFS servers
     [Bernd Schubert].

     (This was asked for but later deemed unnecessary with the
     open-by-handle capability available and caused disagreement as to
     whether it's a security hole or not).

(10) Extra coherency data may be useful in making backups [Andreas Dilger].

     (No particular data were offered, but things like last backup
     timestamp, the data version number and the DOS archive bit would come
     into this category).

(11) Allow the filesystem to indicate what it can/cannot provide: A
     filesystem can now say it doesn't support a standard stat feature if
     that isn't available, so if, for instance, inode numbers or UIDs don't
     exist or are fabricated locally...

     (This requires a separate system call - I have an fsinfo() call idea
     for this).

(12) Store a 16-byte volume ID in the superblock that can be returned in
     struct xstat [Steve French].

     (Deferred to fsinfo).

(13) Include granularity fields in the time data to indicate the
     granularity of each of the times (NFSv4 time_delta) [Steve French].

     (Deferred to fsinfo).

(14) FS_IOC_GETFLAGS value.  These could be translated to BSD's st_flags.
     Note that the Linux IOC flags are a mess and filesystems such as Ext4
     define flags that aren't in linux/fs.h, so translation in the kernel
     may be a necessity (or, possibly, we provide the filesystem type too).

     (Some attributes are made available in stx_attributes, but the general
     feeling was that the IOC flags were to ext[234]-specific and shouldn't
     be exposed through statx this way).

(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
     Michael Kerrisk].

     (Deferred, probably to fsinfo.  Finding out if there's an ACL or
     seclabal might require extra filesystem operations).

(16) Femtosecond-resolution timestamps [Dave Chinner].

     (A __reserved field has been left in the statx_timestamp struct for
     this - if there proves to be a need).

(17) A set multiple attributes syscall to go with this.

===============
NEW SYSTEM CALL
===============

The new system call is:

	int ret = statx(int dfd,
			const char *filename,
			unsigned int flags,
			unsigned int mask,
			struct statx *buffer);

The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat().  There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags.  There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.

Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):

 (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
     respect.

 (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
     its attributes with the server - which might require data writeback to
     occur to get the timestamps correct.

 (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
     network filesystem.  The resulting values should be considered
     approximate.

mask is a bitmask indicating the fields in struct statx that are of
interest to the caller.  The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat().  It should be noted that asking for
more information may entail extra I/O operations.

buffer points to the destination for the data.  This must be 256 bytes in
size.

======================
MAIN ATTRIBUTES RECORD
======================

The following structures are defined in which to return the main attribute
set:

	struct statx_timestamp {
		__s64	tv_sec;
		__s32	tv_nsec;
		__s32	__reserved;
	};

	struct statx {
		__u32	stx_mask;
		__u32	stx_blksize;
		__u64	stx_attributes;
		__u32	stx_nlink;
		__u32	stx_uid;
		__u32	stx_gid;
		__u16	stx_mode;
		__u16	__spare0[1];
		__u64	stx_ino;
		__u64	stx_size;
		__u64	stx_blocks;
		__u64	__spare1[1];
		struct statx_timestamp	stx_atime;
		struct statx_timestamp	stx_btime;
		struct statx_timestamp	stx_ctime;
		struct statx_timestamp	stx_mtime;
		__u32	stx_rdev_major;
		__u32	stx_rdev_minor;
		__u32	stx_dev_major;
		__u32	stx_dev_minor;
		__u64	__spare2[14];
	};

The defined bits in request_mask and stx_mask are:

	STATX_TYPE		Want/got stx_mode & S_IFMT
	STATX_MODE		Want/got stx_mode & ~S_IFMT
	STATX_NLINK		Want/got stx_nlink
	STATX_UID		Want/got stx_uid
	STATX_GID		Want/got stx_gid
	STATX_ATIME		Want/got stx_atime{,_ns}
	STATX_MTIME		Want/got stx_mtime{,_ns}
	STATX_CTIME		Want/got stx_ctime{,_ns}
	STATX_INO		Want/got stx_ino
	STATX_SIZE		Want/got stx_size
	STATX_BLOCKS		Want/got stx_blocks
	STATX_BASIC_STATS	[The stuff in the normal stat struct]
	STATX_BTIME		Want/got stx_btime{,_ns}
	STATX_ALL		[All currently available stuff]

stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.

Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution.  Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.

The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does.  The following
attributes map to FS_*_FL flags and are the same numerical value:

	STATX_ATTR_COMPRESSED		File is compressed by the fs
	STATX_ATTR_IMMUTABLE		File is marked immutable
	STATX_ATTR_APPEND		File is append-only
	STATX_ATTR_NODUMP		File is not to be dumped
	STATX_ATTR_ENCRYPTED		File requires key to decrypt in fs

Within the kernel, the supported flags are listed by:

	KSTAT_ATTR_FS_IOC_FLAGS

[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]

New flags include:

	STATX_ATTR_AUTOMOUNT		Object is an automount trigger

These are for the use of GUI tools that might want to mark files specially,
depending on what they are.

Fields in struct statx come in a number of classes:

 (0) stx_dev_*, stx_blksize.

     These are local system information and are always available.

 (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
     stx_size, stx_blocks.

     These will be returned whether the caller asks for them or not.  The
     corresponding bits in stx_mask will be set to indicate whether they
     actually have valid values.

     If the caller didn't ask for them, then they may be approximated.  For
     example, NFS won't waste any time updating them from the server,
     unless as a byproduct of updating something requested.

     If the values don't actually exist for the underlying object (such as
     UID or GID on a DOS file), then the bit won't be set in the stx_mask,
     even if the caller asked for the value.  In such a case, the returned
     value will be a fabrication.

     Note that there are instances where the type might not be valid, for
     instance Windows reparse points.

 (2) stx_rdev_*.

     This will be set only if stx_mode indicates we're looking at a
     blockdev or a chardev, otherwise will be 0.

 (3) stx_btime.

     Similar to (1), except this will be set to 0 if it doesn't exist.

=======
TESTING
=======

The following test program can be used to test the statx system call:

	samples/statx/test-statx.c

Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.

Here's some example output.  Firstly, an NFS directory that crosses to
another FSID.  Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.

	[root@andromeda ~]# /tmp/test-statx -A /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:26           Inode: 1703937     Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000
	Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

Secondly, the result of automounting on that directory.

	[root@andromeda ~]# /tmp/test-statx /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:27           Inode: 2           Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02 20:51:15 -05:00
Kinglong Mee 7323f0d288 NFSD: Reserve adequate space for LOCKT operation
After tightening the OP_LOCKT reply size estimate, we can get warnings
like:

[11512.783519] RPC request reserved 124 but used 152
[11512.813624] RPC request reserved 108 but used 136

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-02-17 16:26:04 -05:00
NeilBrown b880092109 NFSDv4: use export cache flushtime for changeid on V4ROOT objects.
If you change the set of filesystems that are exported, then
the contents of various directories in the NFSv4 pseudo-root
is likely to change.  However the change-id of those
directories is currently tied to the underlying directory,
so the client may not see the changes in a timely fashion.

This patch changes the change-id number to be derived from the
"flush_time" of the export cache.  Whenever any changes are
made to the set of exported filesystems, this flush_time is
updated.  The result is that clients see changes to the set
of exported filesystems much more quickly, often immediately.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-02-06 17:29:22 -05:00
J. Bruce Fields 32ddd944a0 nfsd: opt in to labeled nfs per export
Currently turning on NFSv4.2 results in 4.2 clients suddenly seeing the
individual file labels as they're set on the server.  This is not what
they've previously seen, and not appropriate in may cases.  (In
particular, if clients have heterogenous security policies then one
client's labels may not even make sense to another.)  Labeled NFS should
be opted in only in those cases when the administrator knows it makes
sense.

It's helpful to be able to turn 4.2 on by default, and otherwise the
protocol upgrade seems free of regressions.  So, default labeled NFS to
off and provide an export flag to reenable it.

Users wanting labeled NFS support on an export will henceforth need to:

	- make sure 4.2 support is enabled on client and server (as
	  before), and
	- upgrade the server nfs-utils to a version supporting the new
	  "security_label" export flag.
	- set that "security_label" flag on the export.

This is commit may be seen as a regression to anyone currently depending
on security labels.  We believe those cases are currently rare.

Reported-by: tibbs@math.uh.edu
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-01-31 12:31:54 -05:00
J. Bruce Fields 5cf23dbb1d nfsd: constify nfsd_suppatttrs
To keep me from accidentally writing to this again....

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-01-31 12:31:54 -05:00
Kinglong Mee 54bbb7d206 NFSD: pass an integer for stable type to nfsd_vfs_write
After fae5096ad2 "nfsd: assume writeable exportabled filesystems have
f_sync" we no longer modify this argument.

This is just cleanup, no change in functionality.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-01-31 12:31:53 -05:00
J. Bruce Fields dcd2086977 nfsd: fix supported attributes for acl & labels
Oops--in 916d2d844a I moved some constants into an array for
convenience, but here I'm accidentally writing to that array.

The effect is that if you ever encounter a filesystem lacking support
for ACLs or security labels, then all queries of supported attributes
will report that attribute as unsupported from then on.

Fixes: 916d2d844a "nfsd: clean up supported attribute handling"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-01-12 15:55:51 -05:00
Linus Torvalds 231753ef78 Merge uncontroversial parts of branch 'readlink' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull partial readlink cleanups from Miklos Szeredi.

This is the uncontroversial part of the readlink cleanup patch-set that
simplifies the default readlink handling.

Miklos and Al are still discussing the rest of the series.

* git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  vfs: make generic_readlink() static
  vfs: remove ".readlink = generic_readlink" assignments
  vfs: default to generic_readlink()
  vfs: replace calling i_op->readlink with vfs_readlink()
  proc/self: use generic_readlink
  ecryptfs: use vfs_get_link()
  bad_inode: add missing i_op initializers
2016-12-17 19:16:12 -08:00
Andreas Gruenbacher 47057abde5 nfsd: add support for the umask attribute
Clients can set the umask attribute when creating files to cause the
server to apply it always except when inheriting permissions from the
parent directory.  That way, the new files will end up with the same
permissions as files created locally.

See https://tools.ietf.org/html/draft-ietf-nfsv4-umask-02 for more
details.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-12-15 20:42:48 -05:00
Miklos Szeredi fd4a0edf2a vfs: replace calling i_op->readlink with vfs_readlink()
Also check d_is_symlink() in callers instead of inode->i_op->readlink
because following patches will allow NULL ->readlink for symlinks.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-12-09 16:45:04 +01:00
J. Bruce Fields e864c189e1 nfsd: catch errors in decode_fattr earlier
3c8e03166a "NFSv4: do exact check about attribute specified" fixed
some handling of unsupported-attribute errors, but it also delayed
checking for unwriteable attributes till after we decode them.  This
could lead to odd behavior in the case a client attemps to set an
attribute we don't know about followed by one we try to parse.  In that
case the parser for the known attribute will attempt to parse the
unknown attribute.  It should fail in some safe way, but the error might
at least be incorrect (probably bad_xdr instead of inval).  So, it's
better to do that check at the start.

As far as I know this doesn't cause any problems with current clients
but it might be a minor issue e.g. if we encounter a future client that
supports a new attribute that we currently don't.

Cc: Yu Zhiguo <yuzg@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-11-01 15:47:52 -04:00
J. Bruce Fields 916d2d844a nfsd: clean up supported attribute handling
Minor cleanup, no change in behavior.

Provide helpers for some common attribute bitmap operations.  Drop some
comments that just echo the code.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-11-01 15:47:52 -04:00
Anna Schumaker 29ae7f9dc2 NFSD: Implement the COPY call
I only implemented the sync version of this call, since it's the
easiest.  I can simply call vfs_copy_range() and have the vfs do the
right thing for the filesystem being exported.

Signed-off-by: Anna Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-10-07 14:54:25 -04:00
Jeff Layton bec782b4fc nfsd: fix dprintk in nfsd4_encode_getdeviceinfo
nfserr is big-endian, so we should convert it to host-endian before
printing it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-09-23 10:18:52 -04:00
Jeff Layton 8a4c392688 nfsd: allow nfsd to advertise multiple layout types
If the underlying filesystem supports multiple layout types, then there
is little reason not to advertise that fact to clients and let them
choose what type to use.

Turn the ex_layout_type field into a bitfield. For each supported
layout type, we set a bit in that field. When the client requests a
layout, ensure that the bit for that layout type is set. When the
client requests attributes, send back a list of supported types.

Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Reviewed-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-15 15:31:32 -04:00
Andrew Elble ed94164398 nfsd: implement machine credential support for some operations
This addresses the conundrum referenced in RFC5661 18.35.3,
and will allow clients to return state to the server using the
machine credentials.

The biggest part of the problem is that we need to allow the client
to send a compound op with integrity/privacy on mounts that don't
have it enabled.

Add server support for properly decoding and using spo_must_enforce
and spo_must_allow bits. Add support for machine credentials to be
used for CLOSE, OPEN_DOWNGRADE, LOCKU, DELEGRETURN,
and TEST/FREE STATEID.
Implement a check so as to not throw WRONGSEC errors when these
operations are used if integrity/privacy isn't turned on.

Without this, Linux clients with credentials that expired while holding
delegations were getting stuck in an endless loop.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-13 15:32:47 -04:00
Benjamin Coddington ac503e4a30 nfsd: use short read as well as i_size to set eof
Use the result of a local read to determine when to set the eof flag.  This
allows us to return the location of the end of the file atomically at the
time of the read.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
[bfields: add some documentation]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-03-23 16:02:39 -04:00
Chuck Lever 4ce85c8cf8 nfsd: Update NFS server comments related to RDMA support
The server does indeed now support NFSv4.1 on RDMA transports. It
does not support shifting an RDMA-capable TCP transport (such as
iWARP) to RDMA mode.

Reported-by: Shirley Ma <shirley.ma@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-03-01 13:06:32 -08:00
J. Bruce Fields 4aed9c46af nfsd4: fix bad bounds checking
A number of spots in the xdr decoding follow a pattern like

	n = be32_to_cpup(p++);
	READ_BUF(n + 4);

where n is a u32.  The only bounds checking is done in READ_BUF itself,
but since it's checking (n + 4), it won't catch cases where n is very
large, (u32)(-4) or higher.  I'm not sure exactly what the consequences
are, but we've seen crashes soon after.

Instead, just break these up into two READ_BUF()s.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-03-01 13:02:57 -08:00
Linus Torvalds 33caf82acf Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "All kinds of stuff.  That probably should've been 5 or 6 separate
  branches, but by the time I'd realized how large and mixed that bag
  had become it had been too close to -final to play with rebasing.

  Some fs/namei.c cleanups there, memdup_user_nul() introduction and
  switching open-coded instances, burying long-dead code, whack-a-mole
  of various kinds, several new helpers for ->llseek(), assorted
  cleanups and fixes from various people, etc.

  One piece probably deserves special mention - Neil's
  lookup_one_len_unlocked().  Similar to lookup_one_len(), but gets
  called without ->i_mutex and tries to avoid ever taking it.  That, of
  course, means that it's not useful for any directory modifications,
  but things like getting inode attributes in nfds readdirplus are fine
  with that.  I really should've asked for moratorium on lookup-related
  changes this cycle, but since I hadn't done that early enough...  I
  *am* asking for that for the coming cycle, though - I'm going to try
  and get conversion of i_mutex to rwsem with ->lookup() done under lock
  taken shared.

  There will be a patch closer to the end of the window, along the lines
  of the one Linus had posted last May - mechanical conversion of
  ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
  inode_is_locked()/inode_lock_nested().  To quote Linus back then:

    -----
    |    This is an automated patch using
    |
    |        sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
    |        sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
    |        sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[     ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
    |        sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
    |        sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
    |
    |    with a very few manual fixups
    -----

  I'm going to send that once the ->i_mutex-affecting stuff in -next
  gets mostly merged (or when Linus says he's about to stop taking
  merges)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  nfsd: don't hold i_mutex over userspace upcalls
  fs:affs:Replace time_t with time64_t
  fs/9p: use fscache mutex rather than spinlock
  proc: add a reschedule point in proc_readfd_common()
  logfs: constify logfs_block_ops structures
  fcntl: allow to set O_DIRECT flag on pipe
  fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
  fs: xattr: Use kvfree()
  [s390] page_to_phys() always returns a multiple of PAGE_SIZE
  nbd: use ->compat_ioctl()
  fs: use block_device name vsprintf helper
  lib/vsprintf: add %*pg format specifier
  fs: use gendisk->disk_name where possible
  poll: plug an unused argument to do_poll
  amdkfd: don't open-code memdup_user()
  cdrom: don't open-code memdup_user()
  rsxx: don't open-code memdup_user()
  mtip32xx: don't open-code memdup_user()
  [um] mconsole: don't open-code memdup_user_nul()
  [um] hostaudio: don't open-code memdup_user()
  ...
2016-01-12 17:11:47 -08:00
NeilBrown bbddca8e8f nfsd: don't hold i_mutex over userspace upcalls
We need information about exports when crossing mountpoints during
lookup or NFSv4 readdir.  If we don't already have that information
cached, we may have to ask (and wait for) rpc.mountd.

In both cases we currently hold the i_mutex on the parent of the
directory we're asking rpc.mountd about.  We've seen situations where
rpc.mountd performs some operation on that directory that tries to take
the i_mutex again, resulting in deadlock.

With some care, we may be able to avoid that in rpc.mountd.  But it
seems better just to avoid holding a mutex while waiting on userspace.

It appears that lookup_one_len is pretty much the only operation that
needs the i_mutex.  So we could just drop the i_mutex elsewhere and do
something like

	mutex_lock()
	lookup_one_len()
	mutex_unlock()

In many cases though the lookup would have been cached and not required
the i_mutex, so it's more efficient to create a lookup_one_len() variant
that only takes the i_mutex when necessary.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-09 03:07:52 -05:00
Christoph Hellwig ffa0160a10 nfsd: implement the NFSv4.2 CLONE operation
This is basically a remote version of the btrfs CLONE operation,
so the implementation is fairly trivial.  Made even more trivial
by stealing the XDR code and general framework Anna Schumaker's
COPY prototype.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-07 23:12:00 -05:00
Kinglong Mee 75976de655 NFSD: Return word2 bitmask if setting security label in OPEN/CREATE
Security label can be set in OPEN/CREATE request, nfsd should set
the bitmask in word2 if setting success.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-31 16:16:40 -04:00
Kinglong Mee 7d580722c9 nfsd: SUPPATTR_EXCLCREAT must be encoded before SECURITY_LABEL.
The encode order should be as the bitmask defined order.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-31 16:16:39 -04:00
Kinglong Mee 6896f15aab nfsd: Fix an FS_LAYOUT_TYPES/LAYOUT_TYPES encode bug
Currently we'll respond correctly to a request for either
FS_LAYOUT_TYPES or LAYOUT_TYPES, but not to a request for both
attributes simultaneously.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-31 16:12:39 -04:00
Kinglong Mee 0a2050d744 NFSD: Store parent's stat in a separate value
After commit ae7095a7c4 (nfsd4: helper function for getting mounted_on
ino) we ignore the return value from get_parent_attributes().

Also, the following FATTR4_WORD2_LAYOUT_BLKSIZE uses stat.blksize, so to
avoid overwriting that, use an independent value for the parent's
attributes.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-31 15:11:05 -04:00
Kinglong Mee c2227a39a0 nfsd: Drop BUG_ON and ignore SECLABEL on absent filesystem
On an absent filesystem (one served by another server), we need to be
able to handle requests for certain attributest (like fs_locations, so
the client can find out which server does have the filesystem), but
others we can't.

We forgot to take that into account when adding another attribute
bitmask work for the SECURITY_LABEL attribute.

There an export entry with the "refer" option can result in:

[   88.414272] kernel BUG at fs/nfsd/nfs4xdr.c:2249!
[   88.414828] invalid opcode: 0000 [#1] SMP
[   88.415368] Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache nfsd xfs libcrc32c iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi iosf_mbi ppdev btrfs coretemp crct10dif_pclmul crc32_pclmul crc32c_intel xor ghash_clmulni_intel raid6_pq vmw_balloon parport_pc parport i2c_piix4 shpchp vmw_vmci acpi_cpufreq auth_rpcgss nfs_acl lockd grace sunrpc vmwgfx drm_kms_helper ttm drm mptspi mptscsih serio_raw mptbase e1000 scsi_transport_spi ata_generic pata_acpi [last unloaded: nfsd]
[   88.417827] CPU: 0 PID: 2116 Comm: nfsd Not tainted 4.0.7-300.fc22.x86_64 #1
[   88.418448] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014
[   88.419093] task: ffff880079146d50 ti: ffff8800785d8000 task.ti: ffff8800785d8000
[   88.419729] RIP: 0010:[<ffffffffa04b3c10>]  [<ffffffffa04b3c10>] nfsd4_encode_fattr+0x820/0x1f00 [nfsd]
[   88.420376] RSP: 0000:ffff8800785db998  EFLAGS: 00010206
[   88.421027] RAX: 0000000000000001 RBX: 000000000018091a RCX: ffff88006668b980
[   88.421676] RDX: 00000000fffef7fc RSI: 0000000000000000 RDI: ffff880078d05000
[   88.422315] RBP: ffff8800785dbb58 R08: ffff880078d043f8 R09: ffff880078d4a000
[   88.422968] R10: 0000000000010000 R11: 0000000000000002 R12: 0000000000b0a23a
[   88.423612] R13: ffff880078d05000 R14: ffff880078683100 R15: ffff88006668b980
[   88.424295] FS:  0000000000000000(0000) GS:ffff88007c600000(0000) knlGS:0000000000000000
[   88.424944] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   88.425597] CR2: 00007f40bc370f90 CR3: 0000000035af5000 CR4: 00000000001407f0
[   88.426285] Stack:
[   88.426921]  ffff8800785dbaa8 ffffffffa049e4af ffff8800785dba08 ffffffff813298f0
[   88.427585]  ffff880078683300 ffff8800769b0de8 0000089d00000001 0000000087f805e0
[   88.428228]  ffff880000000000 ffff880079434a00 0000000000000000 ffff88006668b980
[   88.428877] Call Trace:
[   88.429527]  [<ffffffffa049e4af>] ? exp_get_by_name+0x7f/0xb0 [nfsd]
[   88.430168]  [<ffffffff813298f0>] ? inode_doinit_with_dentry+0x210/0x6a0
[   88.430807]  [<ffffffff8123833e>] ? d_lookup+0x2e/0x60
[   88.431449]  [<ffffffff81236133>] ? dput+0x33/0x230
[   88.432097]  [<ffffffff8123f214>] ? mntput+0x24/0x40
[   88.432719]  [<ffffffff812272b2>] ? path_put+0x22/0x30
[   88.433340]  [<ffffffffa049ac87>] ? nfsd_cross_mnt+0xb7/0x1c0 [nfsd]
[   88.433954]  [<ffffffffa04b54e0>] nfsd4_encode_dirent+0x1b0/0x3d0 [nfsd]
[   88.434601]  [<ffffffffa04b5330>] ? nfsd4_encode_getattr+0x40/0x40 [nfsd]
[   88.435172]  [<ffffffffa049c991>] nfsd_readdir+0x1c1/0x2a0 [nfsd]
[   88.435710]  [<ffffffffa049a530>] ? nfsd_direct_splice_actor+0x20/0x20 [nfsd]
[   88.436447]  [<ffffffffa04abf30>] nfsd4_encode_readdir+0x120/0x220 [nfsd]
[   88.437011]  [<ffffffffa04b58cd>] nfsd4_encode_operation+0x7d/0x190 [nfsd]
[   88.437566]  [<ffffffffa04aa6dd>] nfsd4_proc_compound+0x24d/0x6f0 [nfsd]
[   88.438157]  [<ffffffffa0496103>] nfsd_dispatch+0xc3/0x220 [nfsd]
[   88.438680]  [<ffffffffa006f0cb>] svc_process_common+0x43b/0x690 [sunrpc]
[   88.439192]  [<ffffffffa0070493>] svc_process+0x103/0x1b0 [sunrpc]
[   88.439694]  [<ffffffffa0495a57>] nfsd+0x117/0x190 [nfsd]
[   88.440194]  [<ffffffffa0495940>] ? nfsd_destroy+0x90/0x90 [nfsd]
[   88.440697]  [<ffffffff810bb728>] kthread+0xd8/0xf0
[   88.441260]  [<ffffffff810bb650>] ? kthread_worker_fn+0x180/0x180
[   88.441762]  [<ffffffff81789e58>] ret_from_fork+0x58/0x90
[   88.442322]  [<ffffffff810bb650>] ? kthread_worker_fn+0x180/0x180
[   88.442879] Code: 0f 84 93 05 00 00 83 f8 ea c7 85 a0 fe ff ff 00 00 27 30 0f 84 ba fe ff ff 85 c0 0f 85 a5 fe ff ff e9 e3 f9 ff ff 0f 1f 44 00 00 <0f> 0b 66 0f 1f 44 00 00 be 04 00 00 00 4c 89 ef 4c 89 8d 68 fe
[   88.444052] RIP  [<ffffffffa04b3c10>] nfsd4_encode_fattr+0x820/0x1f00 [nfsd]
[   88.444658]  RSP <ffff8800785db998>
[   88.445232] ---[ end trace 6cb9d0487d94a29f ]---

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-07-20 14:58:22 -04:00
Christoph Hellwig 68e8bb0334 nfsd: wrap too long lines in nfsd4_encode_read
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-22 14:15:05 -04:00
Christoph Hellwig 96bcad5064 nfsd: fput rd_file from XDR encode context
Remove the hack where we fput the read-specific file in generic code.
Instead we can do it in nfsd4_encode_read as that gets called for all
error cases as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-22 14:15:04 -04:00
Christoph Hellwig af90f707fa nfsd: take struct file setup fully into nfs4_preprocess_stateid_op
This patch changes nfs4_preprocess_stateid_op so it always returns
a valid struct file if it has been asked for that.  For that we
now allocate a temporary struct file for special stateids, and check
permissions if we got the file structure from the stateid.  This
ensures that all callers will get their handling of special stateids
right, and avoids code duplication.

There is a little wart in here because the read code needs to know
if we allocated a file structure so that it can copy around the
read-ahead parameters.  In the long run we should probably aim to
cache full file structures used with special stateids instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-22 14:15:03 -04:00
Christoph Hellwig e749a4621e nfsd: clean up raparams handling
Refactor the raparam hash helpers to just deal with the raparms,
and keep opening/closing files separate from that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-19 15:39:51 -04:00
Andreas Gruenbacher 0c9d65e76a nfsd: Checking for acl support does not require fetching any acls
Whether or not a file system supports acls can be determined with
IS_POSIXACL(inode) and does not require trying to fetch any acls; the code for
computing the supported_attrs and aclsupport attributes can be simplified.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-05-29 11:04:02 -04:00
Linus Torvalds 9ec3a646fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-26 17:22:07 -07:00
J. Bruce Fields 6e4891dc28 nfsd4: fix READ permission checking
In the case we already have a struct file (derived from a stateid), we
still need to do permission-checking; otherwise an unauthorized user
could gain access to a file by sniffing or guessing somebody else's
stateid.

Cc: stable@vger.kernel.org
Fixes: dc97618ddd "nfsd4: separate splice and readv cases"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-04-21 16:16:01 -04:00
David Howells 2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Kinglong Mee 1ec8c0c47f nfsd: Remove duplicate macro define for max sec label length
NFS4_MAXLABELLEN has defined for sec label max length, use it directly.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-03-31 16:46:39 -04:00
Kinglong Mee b77a4b2edb NFSD: Using path_equal() for checking two paths
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-03-31 16:46:38 -04:00
Kinglong Mee 376675daea NFSD: Take care the return value from nfsd4_encode_stateid
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-03-25 21:13:02 -04:00
Kinglong Mee db59c0ef08 NFSD: Take care the return value from nfsd4_decode_stateid
Return status after nfsd4_decode_stateid failed.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-03-20 12:43:59 -04:00
Christoph Hellwig 9cf514ccfa nfsd: implement pNFS operations
Add support for the GETDEVICEINFO, LAYOUTGET, LAYOUTCOMMIT and
LAYOUTRETURN NFSv4.1 operations, as well as backing code to manage
outstanding layouts and devices.

Layout management is very straight forward, with a nfs4_layout_stateid
structure that extends nfs4_stid to manage layout stateids as the
top-level structure.  It is linked into the nfs4_file and nfs4_client
structures like the other stateids, and contains a linked list of
layouts that hang of the stateid.  The actual layout operations are
implemented in layout drivers that are not part of this commit, but
will be added later.

The worst part of this commit is the management of the pNFS device IDs,
which suffers from a specification that is not sanely implementable due
to the fact that the device-IDs are global and not bound to an export,
and have a small enough size so that we can't store the fsid portion of
a file handle, and must never be reused.  As we still do need perform all
export authentication and validation checks on a device ID passed to
GETDEVICEINFO we are caught between a rock and a hard place.  To work
around this issue we add a new hash that maps from a 64-bit integer to a
fsid so that we can look up the export to authenticate against it,
a 32-bit integer as a generation that we can bump when changing the device,
and a currently unused 32-bit integer that could be used in the future
to handle more than a single device per export.  Entries in this hash
table are never deleted as we can't reuse the ids anyway, and would have
a severe lifetime problem anyway as Linux export structures are temporary
structures that can go away under load.

Parts of the XDR data, structures and marshaling/unmarshaling code, as
well as many concepts are derived from the old pNFS server implementation
from Andy Adamson, Benny Halevy, Dean Hildebrand, Marc Eshel, Fred Isaman,
Mike Sager, Ricardo Labiaga and many others.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-02-02 18:09:42 +01:00
Christoph Hellwig 4c94e13e9c nfsd: factor out a helper to decode nfstime4 values
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-01-23 10:29:13 -05:00
J. Bruce Fields 0ec016e3e0 nfsd4: tweak rd_dircount accounting
RFC 3530 14.2.24 says

	This value represents the length of the names of the directory
	entries and the cookie value for these entries.  This length
	represents the XDR encoding of the data (names and cookies)...

The "xdr encoding" of the name should probably include the 4 bytes for
the length.

But this is all just a hint so not worth e.g. backporting to stable.

Also reshuffle some lines to more clearly group together the
dircount-related code.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-01-07 14:48:10 -05:00
Linus Torvalds 0b233b7c79 Merge branch 'for-3.19' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
 "A comparatively quieter cycle for nfsd this time, but still with two
  larger changes:

   - RPC server scalability improvements from Jeff Layton (using RCU
     instead of a spinlock to find idle threads).

   - server-side NFSv4.2 ALLOCATE/DEALLOCATE support from Anna
     Schumaker, enabling fallocate on new clients"

* 'for-3.19' of git://linux-nfs.org/~bfields/linux: (32 commits)
  nfsd4: fix xdr4 count of server in fs_location4
  nfsd4: fix xdr4 inclusion of escaped char
  sunrpc/cache: convert to use string_escape_str()
  sunrpc: only call test_bit once in svc_xprt_received
  fs: nfsd: Fix signedness bug in compare_blob
  sunrpc: add some tracepoints around enqueue and dequeue of svc_xprt
  sunrpc: convert to lockless lookup of queued server threads
  sunrpc: fix potential races in pool_stats collection
  sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it
  sunrpc: require svc_create callers to pass in meaningful shutdown routine
  sunrpc: have svc_wake_up only deal with pool 0
  sunrpc: convert sp_task_pending flag to use atomic bitops
  sunrpc: move rq_cachetype field to better optimize space
  sunrpc: move rq_splice_ok flag into rq_flags
  sunrpc: move rq_dropme flag into rq_flags
  sunrpc: move rq_usedeferral flag to rq_flags
  sunrpc: move rq_local field to rq_flags
  sunrpc: add a generic rq_flags field to svc_rqst and move rq_secure to it
  nfsd: minor off by one checks in __write_versions()
  sunrpc: release svc_pool_map reference when serv allocation fails
  ...
2014-12-16 15:25:31 -08:00